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Kolitsidas, Christos
Publications (10 of 20) Show all publications
Zetterström, O., Kolitsidas, C., Jonsson, B. L. & Glazunov, A. A. (2020). A 28-port MIMO Cube for Micro Base Station Applications. IEEE Transactions on Antennas and Propagation, 68(5), 3443-3452
Open this publication in new window or tab >>A 28-port MIMO Cube for Micro Base Station Applications
2020 (English)In: IEEE Transactions on Antennas and Propagation, ISSN 0018-926X, E-ISSN 1558-2221, Vol. 68, no 5, p. 3443-3452Article in journal (Refereed) Published
Abstract [en]

A novel multi-band, dual-polarized, 28-port multiple-input multiple-output (MIMO) cube is presented. The cube structure enables dense placement of the antennas, whilst still allowing for low correlation between the individual antenna ports. The total size of the cube is roughly 2×2×7 λ30, where λ0 is the wavelength at the lowest used frequency. The novelty of the design lies in the use of a combination of orthogonally polarized endfire and broadside radiating antenna elements. Full use of all facets of the cube is achieved without the need to sacrifice bottom or top facets for mounting. Therefore, full azimuthal coverage for communication in two orthogonal polarizations is readily achieved. The system operates in both cellular and Wi-Fi 2:4, 5:5 GHz bands, with a targeted |S11| below –10 dB. The MIMO performance of the system is evaluated in two environments: the Rich Isotropic Multipath environment and the Random Line-of-Sight environment. These two scenarios represent the edge environments of any real-life propagation scenario in terms of the directional distribution of outgoing or incoming waves at a MIMO transceiver. The intended application of the system is micro base stations and repeaters, with possible extension to massive MIMO.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2020
Keywords
Cube antenna, MIMO, Random Line-of-sight, Rich Isotropic Multipath, Antennas, Base stations, Geometry, MIMO systems, Mobile telecommunication systems, Base station applications, Directional distributions, Line of Sight, MIMO transceiver, Multi-path environments, Multipath, Orthogonal polarizations, Radiating antennas, Radio transceivers
National Category
Telecommunications
Identifiers
urn:nbn:se:kth:diva-272299 (URN)10.1109/TAP.2019.2963231 (DOI)000534640900012 ()2-s2.0-85077971258 (Scopus ID)
Note

QC 20200420

Available from: 2020-04-20 Created: 2020-04-20 Last updated: 2024-03-18Bibliographically approved
A. Mouris, B., Kolitsidas, C. & Thobaben, R. (2019). A Dual-Polarized Multi-Antenna Structure for Simultaneous Transmission of Wireless Information and Power. In: 2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, APSURSI 2019 - Proceedings: . Paper presented at 2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, Atlanta, 7 July 2019, through 12 July 2019 (pp. 1805-1806). IEEE, Article ID 8889079.
Open this publication in new window or tab >>A Dual-Polarized Multi-Antenna Structure for Simultaneous Transmission of Wireless Information and Power
2019 (English)In: 2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, APSURSI 2019 - Proceedings, IEEE, 2019, p. 1805-1806, article id 8889079Conference paper, Published paper (Refereed)
Abstract [en]

In this paper, a dual-polarized multi-antenna structure is designed at 2.45 GHz with the goal of allowing simultaneous transmission of wireless information and power. Differential feeding was used to minimize the mutual coupling due to radiation leakage in addition to a mushroom-type EBG structure for suppressing the surface waves. Simulation results for the proposed structure show a mutual coupling level lower than -40 dB between the information transmitting antenna and the power transmitting antennas for both polarizations. The isolation level between the antennas is improved by at least 22 dB and 14 dB for the E-plane and H-plane coupling, respectively.

Place, publisher, year, edition, pages
IEEE, 2019
Series
IEEE Antennas and Propagation Society International Symposium, ISSN 1522-3965
National Category
Telecommunications
Identifiers
urn:nbn:se:kth:diva-269165 (URN)10.1109/APUSNCURSINRSM.2019.8889079 (DOI)000657207106005 ()2-s2.0-85075233043 (Scopus ID)
Conference
2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, Atlanta, 7 July 2019, through 12 July 2019
Note

QC 20220928

Part of proceedings: ISBN 978-1-7281-0692-2

Available from: 2020-03-04 Created: 2020-03-04 Last updated: 2022-09-28Bibliographically approved
Bantavis, P. I., Kolitsidas, C., Empliouk, T., Le Roy, M., Jonsson, B. L. & Kyriacou, G. A. (2018). A Cost-Effective Wideband Switched Beam Antenna System for a Small Cell Base Station. IEEE Transactions on Antennas and Propagation, 66(12), 6851-6861, Article ID 8485638.
Open this publication in new window or tab >>A Cost-Effective Wideband Switched Beam Antenna System for a Small Cell Base Station
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2018 (English)In: IEEE Transactions on Antennas and Propagation, ISSN 0018-926X, E-ISSN 1558-2221, Vol. 66, no 12, p. 6851-6861, article id 8485638Article in journal (Refereed) Published
Abstract [en]

A wideband switched beam antenna array system operating from 2 to 5 GHz is presented. It is comprised of a 4 × 1 Vivaldi antenna elements and a 4 × 4 Butler matrix beamformer driven by a digitally controlled double-pole four-throw RF switch. The Butler matrix is implemented on a multilayer structure, using 90° hybrid couplers and 45° phase shifters. For the design of the coupler and phase shifter, we propose a unified methodology applied, but not limited, to elliptically shaped geometries. The multilayer realization enables us to avoid microstrip crossing and supports wideband operation of the beamforming network. To realize the Butler matrix, we introduce a step-by-step and stage-by-stage design methodology that enables accurate balance of the output weights at the antenna ports to achieve a stable beamforming performance. In this paper, we use a Vivaldi antenna element in a linear four-element array, since such element supports wideband and wide-scan angle operation. A soft condition in the form of corrugations is implemented around the periphery of the array, in order to reduce the edge effects. This technique improved the gain, the sidelobes, and helped to obtain back radiation suppression. Finally, impedance loading was also utilized in the two edge elements of the array to improve the active impedance. The proposed system of the Butler matrix in conjunction with the constructed array can be utilized as a common RF front end in a wideband air interface for a small cell 5G application and beyond as it is capable to simultaneously cover all the commercial bands from 2 to 5 GHz.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2018
Keywords
5G, Butler matrix, edge impedance loading, RF front end, small cell, soft surface, Vivaldi array, wideband, 5G mobile communication systems, Antenna lobes, Base stations, Beamforming, Cost effectiveness, Electric connectors, Microwave antennas, Multilayers, Phase shifters, Small cells, Wide-band
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-247027 (URN)10.1109/TAP.2018.2874494 (DOI)000451994900018 ()2-s2.0-85054504875 (Scopus ID)
Note

QC 20190626

Available from: 2019-06-26 Created: 2019-06-26 Last updated: 2022-06-26Bibliographically approved
Mattsson, M., Kolitsidas, C. & Jonsson, B. L. (2018). Dual-Band Dual-Polarized Full-Wave Rectenna Based on Differential Field Sampling. IEEE Antennas and Wireless Propagation Letters, 17(6), 956-959
Open this publication in new window or tab >>Dual-Band Dual-Polarized Full-Wave Rectenna Based on Differential Field Sampling
2018 (English)In: IEEE Antennas and Wireless Propagation Letters, ISSN 1536-1225, E-ISSN 1548-5757, Vol. 17, no 6, p. 956-959Article in journal (Refereed) Published
Abstract [en]

A dual-band rectenna for radio frequency (RF) energy harvesting is presented in this letter. The proposed antenna has two concentric square patches electrically connected with a small microstrip line connection. Four ports are located in the inner patch. The configuration of the ports enables a differential field sampling scheme and dual polarization. The antenna operates for the WiFi frequency bands of 2.4 and 5.5 GHz with 7.52 and 7.26 dBi gain, respectively, for each frequency. A full-wave Greinacher voltage doubler rectifier for each polarization has been employed for RF-to-dc conversion. The proposed novel topology utilizes the differential field sampling for each polarization and quadruples the overall output voltage by the rectification process. The differential output voltage source from the rectenna can directly act as a power source as typically electronics require differential source for their operation.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2018
Keywords
Differential field sampling, full-wave rectifier, radio frequency (RF) energy harvesting, rectenna
National Category
Telecommunications
Identifiers
urn:nbn:se:kth:diva-231193 (URN)10.1109/LAWP.2018.2825783 (DOI)000434664500005 ()2-s2.0-85045304349 (Scopus ID)
Note

QC 20180720

Available from: 2018-07-20 Created: 2018-07-20 Last updated: 2024-03-18Bibliographically approved
Björkqvist, O., Dahlberg, O., Silver, G., Kolitsidas, C., Quevedo-Teruel, O. & Jonsson, B. L. (2018). Wireless Sensor Network Utilizing Radio-Frequency Energy Harvesting for Smart Building Applications. IEEE Antennas & Propagation Magazine, 60(5), 124-136
Open this publication in new window or tab >>Wireless Sensor Network Utilizing Radio-Frequency Energy Harvesting for Smart Building Applications
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2018 (English)In: IEEE Antennas & Propagation Magazine, ISSN 1045-9243, E-ISSN 1558-4143, Vol. 60, no 5, p. 124-136Article in journal (Refereed) Published
Abstract [en]

The scope of this article is to develop a modular radio-frequency (RF) energy-harvesting system for smart buildings that can act as a power source for sensing devices. Electromagnetic field-strength measurements at the main campus of the KTH Royal Institute of Technology in Stockholm, Sweden, were carried out to define the strength of the available ambient signals. Mainly two spectra were available for possible RF harvesting, i.e., two cellular bands [GSM1800 and third generation (3G)] and the 2.45-GHz Wi-Fi band. Based on these measurements, a modular approach for the system was adopted. The system is composed from two modules: 1) a Wi-Fi rectenna system composed of eight dual-polarized patch antennas and 16 rectifiers to produce eight differential voltage sources connected in series and 2) a cellular rectenna system composed of eight linear tapered slot antennas and eight rectifiers to produce four differential voltage sources connected in series. We propose an innovative multiple-input, single-output (MISO) wave rectifier that yields an efficient differential output. Both rectenna modules offer full azimuthal coverage and can operate either together or independently.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2018
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-237105 (URN)10.1109/MAP.2018.2859196 (DOI)000446796600014 ()2-s2.0-85054801584 (Scopus ID)
Note

QC 2018

Available from: 2018-10-24 Created: 2018-10-24 Last updated: 2024-03-15Bibliographically approved
Mattsson, M., Kolitsidas, C., Silver, G., Björkqvist, O., Dahlberg, O. & Jonsson, B. L. (2017). A high gain Dual-Polarised Differential Rectenna for RF Energy Harvesting. In: 2017 IEEE Antennas and Propagation Society International Symposium, Proceedings: . Paper presented at International Symposium of IEEE-Antennas-and-Propagation-Society / USNC/URSI National Radio Science Meeting, JUL 09-14, 2017, San Diego, CA (pp. 1609-1610). Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>A high gain Dual-Polarised Differential Rectenna for RF Energy Harvesting
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2017 (English)In: 2017 IEEE Antennas and Propagation Society International Symposium, Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2017, p. 1609-1610Conference paper, Published paper (Refereed)
Abstract [en]

A rectenna for radio frequency (RF) energy harvesting is presented in this paper. We introduce a novel technique for RF rectification that is based on differential field sampling and a Greinacher voltage doubler rectifier. The proposed rectification antenna is a dual polarized patch with 4 ports that operates for the WiFi frequency band of 2.4-2.5 GHz and has a gain of 6.75 dB at each port. The proposed novel topology doubles the amount of input power accepted for each polarization and then quadruples the overall output power. In addition we have a differential output voltage source that is typically required for the electronics connected to the harvesting system.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2017
Series
IEEE Antennas and Propagation Society International Symposium, ISSN 1522-3965
National Category
Telecommunications
Identifiers
urn:nbn:se:kth:diva-224111 (URN)10.1109/APUSNCURSINRSM.2017.8072847 (DOI)000424765301349 ()2-s2.0-85042306816 (Scopus ID)978-1-5386-3284-0 (ISBN)
Conference
International Symposium of IEEE-Antennas-and-Propagation-Society / USNC/URSI National Radio Science Meeting, JUL 09-14, 2017, San Diego, CA
Note

QC 20180314

Available from: 2018-03-14 Created: 2018-03-14 Last updated: 2024-03-15Bibliographically approved
Dahlberg, O., Kolitsidas, C., Mattsson, M., Silver, G., Björkqvist, O. & Jonsson, B. L. (2017). A Novel 32 Port Cube MIMO Combining Broadside and Endfire Radiation Patterns for Full Azimuthal Coverage - A Modular Unit Approach for a Massive MIMO System. In: 2017 IEEE Antennas and Propagation Society International Symposium, Proceedings: . Paper presented at International Symposium of IEEE-Antennas-and-Propagation-Society / USNC/URSI National Radio Science Meeting, JUL 09-14, 2017, San Diego, CA (pp. 1641-1642). Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>A Novel 32 Port Cube MIMO Combining Broadside and Endfire Radiation Patterns for Full Azimuthal Coverage - A Modular Unit Approach for a Massive MIMO System
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2017 (English)In: 2017 IEEE Antennas and Propagation Society International Symposium, Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2017, p. 1641-1642Conference paper, Published paper (Refereed)
Abstract [en]

In this paper we propose a novel 32 antenna port multiple-input-multiple-output (MIMO)-cube. The total volume of the cube is 320 x 320 x 120 mm(3) . On two faces, endfire radiating linear tapered slot antennas (LTSAs) are placed and on the remaining sides, a mix of both LTSAs and broadside patch antennas are placed. In total 16 LTSAs and 8 dual polarized patches are used. The LTSA is designed to operate at the GSM and 3G bands, from 1.7 to 2.3 GHz. A corrugation pattern is introduced along the edges of the LTSAs covering one face to increase directivity and decrease sidelobes. The LTSAs are placed in two different orientations in order to receive two polarisations. The patch antenna is dual band and dual polarized. It operates in the frequency bands 2.4-2.5 and 5.45-5.6 GHz where Wi-Fi communication is made. The spatial placement, with antennas on all sides of the cuboid, ensures full azimuthal coverage despite the high directivity of the antennas. Using different antennas on different faces of the cube further optimizes the volume efficiency of the cube for azimuthal coverage.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2017
Series
IEEE Antennas and Propagation Society International Symposium, ISSN 1522-3965
National Category
Telecommunications
Identifiers
urn:nbn:se:kth:diva-224112 (URN)10.1109/APUSNCURSINRSM.2017.8072863 (DOI)000424765301364 ()2-s2.0-85042271618 (Scopus ID)978-1-5386-3284-0 (ISBN)
Conference
International Symposium of IEEE-Antennas-and-Propagation-Society / USNC/URSI National Radio Science Meeting, JUL 09-14, 2017, San Diego, CA
Note

QC 20180314

Available from: 2018-03-14 Created: 2018-03-14 Last updated: 2024-03-15Bibliographically approved
Björkqvist, O., Kolitsidas, C., Dahlberg, O., Silver, G., Mattsson, M. & Jonsson, B. L. (2017). A Novel Efficient Multiple Input Single Output RF Energy Harvesting Rectification Scheme. In: 2017 IEEE Antennas and Propagation Society International Symposium, Proceedings: . Paper presented at International Symposium of IEEE-Antennas-and-Propagation-Society / USNC/URSI National Radio Science Meeting, JUL 09-14, 2017, San Diego, CA (pp. 1605-1606). Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>A Novel Efficient Multiple Input Single Output RF Energy Harvesting Rectification Scheme
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2017 (English)In: 2017 IEEE Antennas and Propagation Society International Symposium, Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2017, p. 1605-1606Conference paper, Published paper (Refereed)
Abstract [en]

In this work an implementation of an ambient radio frequency harvesting system utilizing multiple input single output approach is demonstrated. Measurements of typical ambient radiation have been conducted with respect to power levels and frequency to determine which communication signals are suitable for harvesting. The measurement campaign showed that the WiFi frequency band at 2.45 GHz is a good candidate for indoors applications. A Greinacher voltage doubler is used for the rectification. A multiple input single output - MISO scalable scheme approach is implemented that is able to provide a DC differential output voltage. Simulated and experimental results proved the MISO rectenna to be an efficient scheme for RF harvesting.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2017
Series
IEEE Antennas and Propagation Society International Symposium, ISSN 1522-3965
National Category
Telecommunications
Identifiers
urn:nbn:se:kth:diva-224110 (URN)10.1109/APUSNCURSINRSM.2017.8072845 (DOI)000424765301347 ()2-s2.0-85042291945 (Scopus ID)978-1-5386-3284-0 (ISBN)
Conference
International Symposium of IEEE-Antennas-and-Propagation-Society / USNC/URSI National Radio Science Meeting, JUL 09-14, 2017, San Diego, CA
Note

QC 20180314

Available from: 2018-03-14 Created: 2018-03-14 Last updated: 2024-03-15Bibliographically approved
Bantavis, P. I., Kolitsidas, C., Jonsson, B. L., Empliouk, T. & Kyriacou, G. A. (2017). A Wideband Switched Beam Antenna System for 5G Femtocell Applications. In: 2017 IEEE Antennas and Propagation Society International Symposium, Proceedings: . Paper presented at 2017 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, APSURSI 2017, Manchester Grand Hyatt HotelSan Diego, United States, 9 July 2017 through 14 July 2017 (pp. 929-930). Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>A Wideband Switched Beam Antenna System for 5G Femtocell Applications
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2017 (English)In: 2017 IEEE Antennas and Propagation Society International Symposium, Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2017, p. 929-930Conference paper, Published paper (Refereed)
Abstract [en]

This work introduces a wideband switched beam system for femtocell 5G base stations. The system consists of a 4 x 1 Vivaldi linear array and a 4 x 4 Butler matrix able to operate from 1.9-5.1 GHz. A soft surface is introduced along the outer edges of the vivaldi elements of the array for side lobes and back radiation suppression.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2017
Series
IEEE Antennas and Propagation Society International Symposium, ISSN 1522-3965
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-224107 (URN)10.1109/APUSNCURSINRSM.2017.8072507 (DOI)000424765301015 ()2-s2.0-85042384349 (Scopus ID)978-1-5386-3284-0 (ISBN)
Conference
2017 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, APSURSI 2017, Manchester Grand Hyatt HotelSan Diego, United States, 9 July 2017 through 14 July 2017
Note

QC 20180312

Available from: 2018-03-12 Created: 2018-03-12 Last updated: 2024-03-15Bibliographically approved
Silver, G., Kolitsidas, C., Björkqvist, O., Matsson, M., Dahlberg, O. & Jonsson, B. L. (2017). Exploiting Antenna Array Configurations for Efficient Simultaneous Wireless Information and Power Transfer. In: 2017 IEEE Antennas and Propagation Society International Symposium, Proceedings: . Paper presented at International Symposium of IEEE-Antennas-and-Propagation-Society / USNC/URSI National Radio Science Meeting, JUL 09-14, 2017, San Diego, CA (pp. 1083-1084). Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>Exploiting Antenna Array Configurations for Efficient Simultaneous Wireless Information and Power Transfer
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2017 (English)In: 2017 IEEE Antennas and Propagation Society International Symposium, Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2017, p. 1083-1084Conference paper, Published paper (Refereed)
Abstract [en]

Different patch antenna array configurations for Simultaneous Wireless Information and Wireless Power Transfer - SWIPT - were simulated and evaluated. The scope of the work is to provide configurations that can be used to minimise the interference between information and power transfer as well as provide some beamforming capabilities. Our assumption for all the evaluated structures are that two receive antennas are used for RF energy harvesting and one antenna is used for information exchange. The choice for two antennas for energy harvesting is based on that a differential DC output full-wave rectifier is used. Our analysis is based on patch antennas.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2017
Series
IEEE Antennas and Propagation Society International Symposium, ISSN 1522-3965
National Category
Telecommunications
Identifiers
urn:nbn:se:kth:diva-224108 (URN)10.1109/APUSNCURSINRSM.2017.8072584 (DOI)000424765301090 ()2-s2.0-85042227616 (Scopus ID)978-1-5386-3284-0 (ISBN)
Conference
International Symposium of IEEE-Antennas-and-Propagation-Society / USNC/URSI National Radio Science Meeting, JUL 09-14, 2017, San Diego, CA
Note

QC 20180314

Available from: 2018-03-14 Created: 2018-03-14 Last updated: 2024-03-15Bibliographically approved
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